The subject matter disclosed herein generally relates to signal routing to an electrical device based on a polarity of the signal.
To enable an electrical device (e.g., instrumentation device) to couple to a variety of components (e.g., transducers) that may have either a positive polarity (e.g., AC signal with +12 DC offset) or a negative polarity (e.g., AC signal with a −12 DC offset), multiple terminals in the electrical device with a dedicated terminal for expected voltages may be utilized. However, such devices include unused terminals (depending on the implementation of the device) to be included in the device, thereby increasing production costs of the device inefficiently. Other electrical devices may instead include an analog multiplexer (MUX) circuit coupled between a terminal and internal circuitry to allow a device to be coupled to a variety of components. However, these devices are often vulnerable to damage due to a susceptibility of the MUX to damage caused by electrostatic discharge (ESD) and other shock events. Alternatively, some electrical devices may require a user to manually (e.g., physically) change a configuration to a desired setting (e.g., positive polarity). However, requiring a manual setting may result in a user not changing the setting correctly and/or before each use thereby increasing the likelihood of damage to the electrical device or other unwanted results.
Other electrical devices may instead use large rail amplifiers (e.g., allow a 36V variance) to increase a tolerated voltage range in a signal on a single pin. However, large rail amplifiers typically sacrifice accuracy for flexibility and are often unable to achieve the accuracy requirements for many implementations (e.g., measurement systems). Moreover, large rail amplifiers also are more expensive than traditional amplifiers. Furthermore, large rail amplifiers are becoming more rare in implementation, thereby reducing the demand, production, and support of large rail amplifiers.
As an alternative to large rail amplifiers, some electrical devices may attenuate the signal as it enters into an input module. However, by reducing the amplitude of the signal, the electrical device also significantly reduces the signal-to-noise ratio of the attenuated signal. By reducing the signal-to-noise ratio, electrical devices that attenuate the input signal often are unable to produce accurate outputs for small input ranges.